So ever since I got my SC a couple months ago, I've been getting this stupid O/D flash. My car will not shift into 4th gear at all...

I checked the codes and it threw code 42, vehicle speed sensor. I looked this up, searched around, and all I found was something about taking out the dash and splicing a pink wire to a red/blue wire? Is this the solution to my problem? I don't want to start hacking up my wires for no reason.

Help me! My RPM's are terrible and I'm guzzling gas.

 

As I recall there are 2. I attached a thread you might want to look at so you can locate them and trouble shoot. As I remember the one on the passenger side was the one that sends the signal to the speedometer. If your speedometer is erratic or not working that may point you in the right direction. Read through this and see if it helps. Good luck and post with any questions or results to help others. https://www.clublexus.com/forums/per...ed-sensor.html

 

Thanks for the help. The odd thing is, my speedo works fine, as well as the RPM's. So does that mean it's something else?

 

I have exactly the same problem! Got my 92 SC3 close to month ago, since I got it, never switched to fourth, and my o/d is blinking all the time. If im doing 70 on a highway i gotta run at 4k rpm...never troubleshot my tranny, but i believe its the same code as yours, i'll read on that problem on my own and if i find a solution will let you know.

 

Yup exactly my problem. Thanks, some help in researching would be great! I hate this problem.

 

Code 42 is an elusive beast --for me at least.

I'm assuming SC 300 (A340)

You've probably seen the repair manual. Code 42 is related to drivers side speed sensor No.1 on the transmission. Since you actually can't get overdrive, I would guess either the No1/No2 shift solenoid or the actual speed sensor No. 1 needs to be replaced.

I have had the code for 4 years without remedy. My transmission, though is the aristo/supra TT and has worked perfectly though. I did go the route of wire splice behind the inst cluster with no success. Some have when it is a signal strength issue but I doubt that is the issue in this instance.

If there have been significant mods/wiring harness changes (like mine), it gets a little more complex. If not, I would stick with the two above probable culprits.

 

Guys: Check out my reply here on issues with trannies not going into overdrive or 4th or 5th gear and/or error code 42. It's probably an issue w/ the ECM or capacitors inside the ECM:
https://www.clublexus.com/forums/sc-...ml#post8725659